SOTABEAMS BANDHOPPER

 

I have been thinking for a while that although verticals are truly handy to deploy and take up little space, 40m would benefit from a simple dipole.  So what to do?  Do I make one up?  I certainly could.  I have done it many times before.  I would then need a mast of some kind to support it, plus guys and feeder.

It would then have to be packable and easy to carry if I was away from the car.  Do I make it a single band or multiband? Can I get decent lightweight wire that won't stretch in use?  How light can I make it?

Fortunately, SOTABEAMS have already invented this and have variations on it!

From the outset, I should state that I have nothing to do with SOTABEAMS and I bought this setup with my own money.  The opinions in this article are my own and based on my own findings.

The Bandhopper range consists of a series of linked dipoles.  The 4 band (80,40,30,20), 3 band (40,30.20) and the 2 band (40,20).  Each one is pretuned, alleviating the need for a tuner.  Great for radios like the QCX,  Of course, the 40m element would also tune on 15m.

These are completely self contained link dipoles.  They come on 3 winders and include feeder, terminated on a BNC connector, and a backstay.  The wire and associated cords are bright and easy to see, important if you are anywhere near the public.  The centrepiece is designed to drop over the top of a 'fishing pole' type of mast, although you could use a cable tie to help support it on other kinds of support.  The feeder includes a nice choke balun and the dipoles are linked via crocodile clips.  The whole thing comes in a bag with 3 well engineered ground pegs.  The whole thing weighs less than 500g!

The design of this aerial is superb.  There are even elastic straps built in to keep everything tidy on the winders.  Winding the aerial and feeder onto the winders in a 'figure of eight' style, stops everything tangling.

Now, all this isn't new to a lot of people who have been using these for years on SOTA activations but it is new to me and I am impressed!

So the next thing to think about is supporting the dipole.

I could buy a cheap fishing pole mast.  I have used these many times in the past for 1/4 wave verticals.  The problem that most of these suffer from is the top sections are very whippy.  If the mast is to support a dipole, the last thing you want it for the top to be bending over and potentially snapping over time.  They also tend to be relatively long and not easy to carry without holding them.

Enter the Tactical Mini 6m pole.

This is a good heavy duty pole that, when in its packed form is only 22 inches long!  It is recommended for the 2 and 3 band Bandhoppers.  It comes in a nicely made bag and is well thought out and constructed and weighs 750g.

The great thing about this setup is that it is totally self supporting.  I suspect that in really windy conditions, an extra set of guys would be useful and SOTABEAMS have you covered there too but for me, I doubt it would ever be.a problem as I am very much a fair weather portable operator :)

Once in the air, the two legs of the dipole and the inbuilt backstay form the three guys as well.  This will take a little practice but once mastered will mean the aerial can be erected in very little time at all.

There is a video on the SOTABEAMS website by Richard, G3CWI, showing how this is achieved.  Very simple and easily doable by one person!

Obviously, changing bands will inevitably mean lowering the mast over  again but that it just a matter of dropping the backstay and lowering to the ground, linking, then erecting the mast again.  The job of only a couple of minutes.

I have a couple of questions about the setup that I would like to have answered if anybody knows?

Firstly, SOTABEAMS state ...

'This is about 6 metres (20ft) up and is the perfect height for the antenna centre. Any higher and the antenna may not work properly'

Now the accepted rule for dipoles that I have always been told, is that to work for a given band, the centre of the dipole should be at least 1/2 wave off the ground.  For 40m, this is about 10m, or 33 feet.  So, I find this interesting and is possibly a gap in my knowledge.  Can anybody help me here?

Secondly, when supported in this way, the two legs of the inverted V will also be less than 180 degrees apart, probably approaching 120 degrees.  This would make it somewhat directional I would have thought.  Does anyone have any experience of this or is this just another case of overthinking on my part?

I guess the truth will become apparent as I gain experience with the aerial :)

I know this aerial is much loved by those who use it and I look forward to trying it out!

Here is a quick unboxing of the aerial and mast.

73 Ian